Paper disintegrator



United States Patent App]. No. Filed Patented Priority PAPER DISIN'I'EGRATOR 2 Chili, 2 Dram l-fls.

U511. 100/97, l00/l45: 241/48, 241/56 Int. Cl.

[56] References Cited UNITED STATES PATENTS 1,977,77l 10/ l934 Mahan 24l/56X 3,189,286 6/l965 O'Connor l00/97X Primary Examiner-McGehee Attorney-Waters, Roditi, Schwartz & Nissen ABSTRACT: A paper disintegrator comprising a shaft with hammers and a material-conveying fan mounted thereon, the material-conveying fan being parted off the hammers by a perforated bottom. Mounted at the outlet opening of the paper disintegrator is a compacting device, for example, a screw conveyor, the outside diameter of which corresponds to the inside diameter of the outlet opening. The paper disintegrator is provided with ducts for directing the air, sucked by the fan, to the inlet portion of the machine for providing circulation of air within the paper disintegrator.

The efficiency of this disintegrator exceeds by more than two times the efficiency of the known disintegrating apparatus at the same overall dimensions.

PATENIEU UEC29 I976 SHEET 2 BF 2 3 m m 0 0 U 0 0 ow nwo 0000 1 J 0 0 0 0 0 0 0 0 0 O O O O 0 000 U 0 0 %0 N 0 0 0 00000 0 W O O O O 0 0 O 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 O O 0 000 O 0 000 O OAWUOHAVUOO 0 0 m m 0 o oo wo 0% 00 O 0 O 0 2 000000 000000 00000 0000000 0 0 0 7 00 6 1 w PAPER DISINTEGRATOR The present invention relates generally to paper disintegrating apparatus and more specifically has reference to dry-type paper disintegrators, particularly adapted for office use for destroying paper of all kinds, and is especially useful where it is necessary to destroy classified material to the point of a complete loss of identity, to a finely ground dry pulp.

Known in the art is a paper disintegrator having a shaft with a plurality of beater arms or socalled hammers which is coaxially connected to a shaft of an electric motor mounted in the lower portion of the disintegrator housing and parted from the hammers by a grid. The housing of such an apparatus has a material-receiving opening in its upper portion and a perforated bottom wall in the form of a grid for discharging the disintegrated paper in its lower portion. Mounted under the perforated bottom wall is a centrifugal material conveying blower. The impeller of the blower is mounted on a shaft of an electric motor whose axle is aligned with the vertical axis of symmetry of the housing and with the axle of the electric motor rotating the shaft with the hammers. The disintegrator is provided with an outlet throat connected through a flexible hose with a receiver for collecting the disintegrated paper in the form dry pulplike mass. The latter is conveyed through the disintegrating apparatus into the receiver by an airflow produced by the centrifugal blower. In this case the air is sucked into the apparatus through the material-receiving opening and discharged therefrom through a dust catching filter mounted near the receiver for collecting the pulplike mass or combined with it (as an example, see the technical description of such an apparatus made by the French company Bregix, 1965).

The known apparatus of the above type are disadvantageous in that during the operation their efficiency is limited by the efficiency of the employed dust catching filters, i.e. on the dimensions of these filters. A room where such an apparatus is installed becomes dusted since the filters do not ensure complete trapping of the paper dust.

Furthermore, the pulplike paper mass is fed into the collecting receiver as a loose material inconvenient for subsequent transportation, as in this case'a great number of removable bags is needed.

To prevent dusting of the air in the operating room there should be provided a tight connection between the limitedcapacity receiver for collecting the pulplike mass and the outlet throat of the disintegrating apparatus; however, when frequently changing the pulp receivers the tightness of the connection is disturbed and the efficiency of the apparatus is reduced.

A principal object of the invention is to provide such an apparatus for dry disintegration of papers in which the leakage of air and dust from the apparatus is considerably reduced, while the transportability of the dry pulplike mass and efficiency of the apparatus are increased. 7

This object is attained by providing a paper disintegrator comprising a shaft with hammers and a material conveying fan mounted thereon, the fan being parted off these hammers by a perforated bottom wall in which apparatus. according to the invention, the outlet opening of the disintegrator is provided with a device for compacting dry pulplike paper mass, preferably a screw conveyor, the outside diameter of which corresponds to the inside diameter of the outlet opening, and in which there are provide provided ducts for directing the air sucked by the fan to the inlet of the disintegrator to ensure air circulation within this apparatus.

Such a construction of the disintegrator helps to obviate the use of external dust catching filters and to practically avoid any escape of dust-laden air from the disintegrator into the room in which it is mounted. This apparatus makes it possible to produce a transportable dry pulplike mass due to its being compacted with the help of a screw conveyor.

In a preferable embodiment of the invention the disintegrat ing apparatus may be provided with a double-walled housing. Such a construction makes it possible to use the space between the walls as a duct for directing the air sucked by the fan to the inlet portion of the apparatus.

The present invention is advantageous in that the efficiency of the disintegrator is increased by more than two times. its overall dimensions remaining the same.

A preferable embodiment of the invention is further described by way of example with reference to the accom' panying drawings, in which:

FIG. 1 is a longitudinal section of the apparatus according to the invention;

FIG. 2 is a cross section along the line ll-ll in FIG. I.

The paper disintegrator has a shaft 1 (FIGS. l, 2) mounted in bearings 2 and 3 and fixed to the upper bottom wall 4 and lower bottom wall 5 of the housing 6. Mounted on the shaft l are hammers 7 to 12 secured in recesses of discs 13 to 16 by means of pins 17. These discs are-connected to the shaft through a key.

Two upper hammers are arc-shaped and have toothed external cutting edges. These hammers are pivoted so that they can be turned through a certain angle about the axis of the pins 17 which are eccentrically mounted mounted in the discs 13 and 14. Mounted on the shaft 1 is a sleeve 18 carrying helically bent rods 19.

The hammers 9 to T2 are made in the form of cutters with straight cutting edges and are rigidly secured in the recesses of the discs 15 and 16.

The hammers 7 to 11 are located on the shaft 1 along a helical line. The hammers l1 and 12 are arranged in the same horizontal plane, diametrically opposed to each other.

The sleeve 18 and the discs 13 to 16 are secured on the shaft 1 by means of a nut 20. The end of the shaft l is disposed above the upper bottom wall 4 and carries a pulley 21. while the other end is disposed under the lower bottom 5 and carries a flywheel 22 on which blades of the fan 23 are mounted.

The shaft 1 is rotated by an electric motor 24 through a V- belt transmission 25.

The upper portion of the housing has a material-receiving opening 26 closed with elastic cover plates.

Mounted between the hammers and the material conveying fan is the bottom 5 with adjustable openings for discharging the pulplike paper mass from the grinding zone into the chamber 27 of the housing.

The internal walls of the housing accommodate guide members 28 located along helical lines and braking pins 29 disposed in vertical rows. The upper portion of the walls of the housing is provided with one or several ports 30.

The lower portion of the disintegrator housing comprises a compacting device in the form of a screw conveyor M the outside diameter of which corresponds to the inside diameter of the outlet opening 32 of the disintegrator. The screw conveyor partially enters the outlet opening. it is rotated by an electric motor 33 through a reduction gear 34 and a shaft 35 on which a key 36 is mounted. The drive of the screw conveyor is made so that the screw performs both rotary and reciprocating motions and during the movement of the pin 37 rigidly secured to the housing along the helical slot provided in the flange of the conveyor it slides on the shaft 35.

A conically-shaped throat 38 is secured to the cabinet behind the outlet opening.

The electric motors 24 and 33, the reduction gear 34 and the starting electrical equipment are mounted outside the housing of the paper disintegrator and are closed with a pivoted cover 39.

The paper disintegrator operates in the following manner.

The paper documents to be destroyed amounting to sheets with a maximum format of 270 X 300 mm. are introduced into the disintegrator through the material-receiving opening 26. The airflow produced by the fan conveys the paper to the grinding zone; the paper is thrown by the rods 19 to the internal walls of the housing. In the grinding zone the paper is preliminarily disintegrated by the pivoted rotary hammers 7 and 8 and then is subjected to the final disintegration by the rotary hammers 9 to 12. The inclined guide members 28 provide for gradual directed delivery of the paper to the grinding zone for final disintegration. With the help of the rods 29 the rotary motion of the paper is slowed down thus ensuring an intensive grinding of the paper.

The dry pulplike paper mass through the opening in the bottom wall is conveyed by the airflow into the chamber 27 and then to the screw conveyor 31.

The pulplike paper mass is caught by the screw conveyor 31 and fed to the outlet of the apparatus through the conicallyshaped throat 38 whose tapering as well as the correspondence of the outside diameter to the inside diameter of the outlet throat contribute to partial compacting of the paper mass to provide a tight plug at the outlet of the disintegrator and to prevent the main airflow against escaping through the throat. For discharging the air from the lower portion of the disintegrator ducts 40 are provided, which are formed by the space between the walls of the disintegrator housing. The air through these ducts and through the port 30 is fed to the upper receiving portion of the disintegrating apparatus and after that the airflow is again directed along the same path.

The circulation of air within the disintegrator makes it possible to exclude the dust catching filters and to practically eliminate an escape of dust-laden air from the apparatus.

This makes it possible to increase the efficiency of the paper disintegrator without increasing its overall dimensions.

The compacting device, that is, the screw conveyor 31,

which performs rotary and reciprocating motion. provides for an additional compacting of the pulplike mass discharged from the conically-shaped throat 38. As this takes place. the paper mass is made 5() times more compact as compared with noncompacted paper mass produced by the paper disintegrators known heretofore. I

We claim: a

l. A paper disintegrator comprising, in combination, a housing with an inlet opening in the upper portion of this housing and with an outlet opening in the lower portion ot this housing; a shaft with hammers and a material-conveying tan mounted on this shaft which is arranged within said housing in a vertical position; a perforated partition wall between said hammers and said material-conveying fan; a material compacting device comprising a screw conveyor. disposed at said outlet opening of said housing, the outside diameter of said screw conveyor corresponding to the inside diameter of said outlet opening; ducts in said paper'disintegrator for directing the air, sucked by said material-conveying fan, to the inletportion of said housing for providing circulation of air within said paper disintegrator.

2. A paper disintegrator as claimed in claim 1, wherein said housing has double walls, the space between the walls being used as said ducts for directing the air, sucked by the materialconveying fan, to the inlet portion of said housing. 

